Whisk the egg whites until stiff and set aside.

Whisk the egg yolks and sugar (with the Marsala if using) for a few minutes until pale, voluminous and fluffy – this is what we can zabaglione!

Switch from a whisk attachment to a paddle mixer, and beat in the mascarpone until nicely combined.

Finally, fold in the egg whites in a couple of batches.

Place into a piping bag ready to assemble and store in the fridge until ready to use.

Quickly dip a Savoiardi biscuit in the brewed espresso (you don’t need to do this for very long as you don’t want the biscuits to become overly soaked – results in a gross and watery texture later on!) and place at the base of your dish. Repeat with biscuits until you have a complete layer.

Spread over an even layer about 2cm thick of the mascarpone cream then dust with cocoa powder.

Repeat until you reach the top of your dish (I ended up with 5 layers of biscuits) – finishing with a layer of cream and a generous dusting of cocoa powder.

You do really need to refrigerate for at least a 3-4 hours before serving to ensure the cream has a chance to set and you get that beautiful, mousse-like finished texture.